The case involves a failed partnership with a Mexican company, Worldwide Directories, to publish print and online telephone directories in Mexico. The companies had taken steps to expand the partnership internationally, which is why the damages ended up being in the billions of dollars; the court ruled that Yahoo had improperly terminated its agreement, which led to not just an actual loss of business in Mexico but potential gains in countries as far afield as France, Korea, and Australia.

Yahoo has said it plans to "vigorously" appeal the judgment against it, which it has characterized as "nonfinal." As with civil cases in the U.S., cases can be appealed in the Mexican courts. The judgment is also not final in that the court has not finished calculating all the damages it says Yahoo owes Worldwide Directories.

If the judgment is upheld, Yahoo could face the loss of a large portion of its cash reserves, some of which it had planned to distribute to shareholders and some of which it may have hoped to use for acquisitions.

Yahoo has already had one change of legal representation: As we reported earlier this month, the lawyer who handled its defense in the case, Fabio Corominas de la Pera, is no longer with Baker & McKenzie, a multinational law firm. That firm told Business Insider that a new layer, Alfonso Cortez-Fernandez, is now handling the case for Yahoo.

Yahoo and Baker & McKenzie have not responded to requests for comment on the new law firm's role.

Carlos Bazan-Canabal, a cofounder of Worldwide Directories, has hired Orrick Herrington & Sutcliffe to represent his company in the U.S.